Method for treatment of a region of the skin of a human subject, in particular cosmetic treatment by the trans-epidermal route using projection of a liquid under pressure

ABSTRACT

The invention concerns a method for the treatment, in particular cosmetic, of an area of the skin of a human subject transepidermally, comprising the step consisting of spraying a pressurised liquid onto the area to be treated, by means of a spray nozzle ( 25 ). The invention also concerns a device for implementing such a method, as well as a hand piece for such a device.

The invention concerns a method for the treatment, in particularcosmetic, of an area of the skin of a human subject transepidermally, aswell as a device for implementing such a method, and a hand piece forsuch a device.

Methods of rejuvenating the skin are already known, such as lasermethods, chemical peelings, mesotherapy techniques, injections ofcollagen and other products, resorbable or not, or methods of abradingthe skin by spraying abrasive powders.

However, these methods have several drawbacks: they are in fact liableto cause pain and/or secondary effects.

In addition they are usually socially incapacitating for the patients,since the skin, having been highly stressed, regains its normalappearance only after a significant lapse of time.

To mitigate these drawbacks, the invention proposes a method for thetreatment, in particular cosmetic, of an area of the skin of a humansubject transepidermally, intended in particular to allow therejuvenation of the skin and/or improvement to imperfections of theskin.

Implementing this method makes it possible to make active substancespenetrate through the epidermis, without causing any significantincapacitation. Thus, once the treatment is ended, the skin regains itsnormal appearance within a very short period of time, ranging from a fewminutes to a few hours, and the patients can consequently resume theirnormal activities very rapidly.

In addition, this method requires no anaesthesia, and does not cause anypain in the patient. It makes it possible to make active productsintended to improve particularly the appearance of the skin, for examplehydration, penetrate deeply.

To this end, and according to a first aspect, the invention proposes amethod for the treatment, in particular cosmetic, of an area of the skinof a human subject transepidermally, comprising the step consisting ofspraying a liquid under pressure on the area to be treated, by means ofa spray nozzle.

According to a second aspect, an object of the invention is a device forthe treatment of an area of the skin of a human subjecttransepidermally, comprising a spray nozzle, and comprising means ofpressurising a liquid, and at least one conduit disposed between thepressurising means and the spray nozzle.

According to a third aspect, the invention concerns a hand piece forsuch a device, comprising control means arranged so as, in the idleposition of the said hand piece, to stop the pressurised liquid throughthe contact of the end of the piston on a piece and, in the position ofuse, to move away the said end of the piece, so as to release the liquidin order to supply the spray nozzle.

Other objects and advantages of the invention will emerge during thefollowing description given with reference to the accompanying drawings,in which:

FIG. 1 is a schematic front view of a device for implementing the methodaccording to the invention;

FIG. 2 is a schematic view of the elements forming the device of FIG. 1,according to a first embodiment in which the device functions in opencircuit;

FIG. 3 is a schematic view of the elements forming the device of FIG. 1,according to a second embodiment in which the device functions in closedcircuit;

FIG. 4 is a schematic view of the means of pressurising the device ofFIG. 1 according to one embodiment;

FIG. 5 is a view in section of a hand piece forming part of the deviceof FIG. 1, according to a first embodiment, comprising a nozzle forspraying a pressurised liquid;

FIGS. 6 a and 6 b are respectively a view in section and a plan view ofa hand piece forming part of the device of FIG. 1, according to a secondembodiment;

FIGS. 7 a, 7 b and 7 c are respectively partial views in section of thehand piece of FIG. 5, showing the form of the liquid jet sprayed ontothe skin, according to three variants;

FIG. 8 is a schematic view of the elements forming the device of FIG. 1,according to a variant of the second embodiment in which the devicefunctions in closed circuit.

The method according to the invention is intended to allow penetrationof active substances through the epidermis.

According to this invention, this method comprises a step consisting ofspraying a pressurised liquid through a nozzle onto an area to betreated.

This method is implemented by a device 1 like the one depicted inFIG. 1. This device 1 comprises a housing 2 in which means ofpressurising a liquid and means of sucking out the said liquid aredisposed, a control keypad 3, bags 4 intended to receive one or moreliquids, and a hand piece 5 enabling an operator to implement the saidmethod.

According to one embodiment, depicted in FIGS. 2 and 3, the means ofpressurising the liquid comprise a pump 6 which can be a piston ormembrane pump, able to confer on the liquid a pressure able to varybetween 5 and 70 bar. The pressurisation means are associated with meansof controlling and measuring the pressure, comprising, in the directionof circulation of the liquid, a damper 7, a pressure switch 8, apressure gauge 9, a decompressor 10 and a solenoid valve 11.

According to another embodiment, depicted in FIG. 4, the pressurisationof the liquid can be effected by an enclosure 12 in which the flexiblebag 4 containing the liquid is placed, the said chamber 12 beingpressurised for example by a bottle of air or nitrogen 13, or by ablower.

These pressurisation means make it possible to bring the pressurisedliquid through a conduit 14 as far as the hand piece 5, by virtue ofwhich the said liquid is sprayed onto an area of the skin.

The hand piece 5 will be described below in detail.

After having been sprayed onto the skin, the liquid is sucked up througha conduit 15. The suction means comprise a vacuum pump 16 associatedwith filtration means 17, as well as means of controlling and measuringthe vacuum comprising a vacuum meter 18, a vacuum switch 19 and asolenoid valve 20.

FIG. 2 depicts a first embodiment of the device, in which the latterfunctions in open circuit. In this embodiment, the liquid is ejectedafter its suction into a jar 39 provided for this purpose.

According to a second embodiment, depicted in FIG. 3, the devicefunctions in closed circuit. To this end, after suction of the liquid,the latter is put in circulation again, passing through a filter 21, soas to retain the impurities and skin waste contained in the liquid, andthen the liquid is recycled, once again passing through the circuit.This arrangement has the advantage, for the same subject, of using alesser volume of solution.

According to a variant of the second embodiment (FIG. 8), thisarrangement is implemented when the circuit comprises a sterileenclosure pressurised in an enclosure 12, through which the liquidpasses, so as to prevent any risk of contamination. In this variant, allthe components in contact with the liquid are adapted to thesesterilisation conditions.

The hand piece 5 is now described in relation to FIGS. 5 and 6.

This hand piece 5 has the conduit 14 passing through it. It consists ofa body 22 whose material can withstand passing through an autoclave witha view to its sterilisation.

The hand piece 5 is provided with an on/off valve, not shown, intendedto control the spraying of the liquid. In a variant, this valve can bedisposed on the body of the device 1, but this arrangement has thedrawback of resulting in a residual flow of the liquid remaining in theconduit 14.

The hand piece 5 is provided with an end piece 30 which can be unscrewedor detached, intended to obtain a vacuum on the skin, the said end piece30 being rounded in shape, so as not to damage the surface of the skinto which it is applied.

The hand piece 5 also comprises a demountable or detachable nozzleholder 23, on which a spray nozzle 25 is mounted, also demountable, andsterilisable, intended to spray the pressurised liquid onto the area tobe treated. Liquid arrives at this spray nozzle 25 via the conduit 14.

The spray nozzles 25 used are formed from a material of high hardness,such as tungsten carbide.

They make it possible, according to their geometry, to form jets ofliquid of various shapes, various widths, or various focal distances.All variants are shown in FIGS. 7 a, 7 b and 7 c, which show jets 26whose shape is respectively of the triangular pencil type, or solid cone(FIG. 7 a), of the hollow cone type (FIG. 7 b) and of the flat jet type(FIG. 7 c).

The hand piece 5 also comprises an annular suction chamber 27 connectedby the conduit 15 to a collector 28, so as to allow suction of theliquid after it is sprayed onto the skin.

In the embodiment depicted in FIG. 6, the hand piece 5 comprises a body29 and an end piece 30 mounted on the body 29, the open end of whichencloses the spray nozzle 25.

In the idle position of the hand piece 5, the pressurised liquid isstopped by contact of the end 32 of the piston 36 on the piece 33.

This hand piece also comprises control means comprising a control lever34, an electrical contactor 35 and a piston 36. These control means makeit possible, when a user exerts pressure on the liquid 34, to move theend 32 of the piece 33 away, so that the orifice 37 of the conduit 14′releases the liquid, which then fills the distribution chamber 31 and,by means of the conduit 38, supplies the spray nozzle 25.

The said control means are also arranged so as to control thefunctioning of the means of sucking the liquid after it is sprayed ontothe skin. These suction means comprise an annular section 15′ and acylindrical conduit 15.

The sprayed liquid comprises typically water, or saline possibly mixedwith one or more additives for cosmetic, therapeutic or anaesthetic use.

One embodiment of the method according to the invention is nowdescribed.

In order to facilitate the penetration of the active substances, themethod of treating the skin transepidermally can be preceded by a stepof abrasion of the stratum corneum and possibly of the upper layers ofthe epidermis by means of abrasive products such as crushed pits,aluminium hydroxide, glass or ceramic microballs, or any other abrasiveproduct having for example a granulometry of around 100 to 125 microns.

This step is implemented by a hand piece 5′ (FIG. 1), arranged so as toallow the abrasion of the skin by abrasive products. Thus it is possibleto use quantities of additives in small proportions in the step ofspraying the liquid.

The abrasion of the stratum corneum and the pressure conferredthereafter on the jet of liquid make it possible to make the productswhich, in cosmetic form, normally penetrate only the upper layers of theepidermis, penetrate deeply into the epidermis.

The solution intended to be sprayed onto the skin can then be preparedby injecting one or more additives, by means of a syringe or a needle,into the flexible bag 4 containing sterilised water, or saline.

It is also possible to use solutions prepared extemporaneously orproducts existing commercially.

Then, as soon as this injection is performed, the following step of themethod is implemented. Thus the solution remains stable and the additiveor additives remain soluble in solution.

The following step consists of forming a vacuum on the skin, and thenthe pressurisation means are activated so as to allow a spraying of thesolution under pressure onto the skin of the subject, by means of thespray nozzle 25.

A safety device ensures that the pressurisation means are set inoperation only when the said vacuum is formed on the skin, so as toprevent any unwanted spraying of solution.

The spraying of the said solution is carried out at a pressure such thatthere is no risk of breakage of the skin, whilst imposing a maximumpressure for effective penetration of the said solution.

In a particular example, the pressures used are between 10 and 25 bar,so as to allow effective penetration of the solution into the skin.

In a particular example, the flow rates used are between 100 and 250ml/minute. When the solution is sprayed onto the face of the subject,the duration of this step is around a few minutes, the volume ofsolution used typically being around 1 to 2 litres.

As the said solution is sprayed, this is sucked into the suction chamber27, with a view to its discharge through the conduit 15. The solution isthen stored in a jar 39 (FIGS. 2 and 3) so as to be thrown away afterits use (open-circuit operating mode) or filtered so as to be recycled(closed-circuit operating mode).

The additives used can be trace elements (zinc, silicon, selenium etc),vitamins (A, E, C, K etc), acids such as fruit acids (sugar cane,grapefruit etc), trichloracetic, kojic, hyaluronic, salicylic etc acids,mineral salts, plant extracts, or any other additive chosen according toits specific properties. These properties may result, for example, inhydrating, anti-free radical, regenerating, restructuring, exfoliating,softening, nourishing, anti-inflammatory, healing, whitening ordepigmenting functions, this list of course not being exhaustive.

Other additives can also be used, such as anaesthetics.

By way of example, the following additives can be used:

-   -   muscat rose oil or grape seed oil, for their skin regenerating        and restructuring properties;    -   horsetail extract, for its regenerating and firming action;    -   tocopherol, vitamin E, having anti-radical properties;    -   sugar cane α-hydroxyacid (AHA), for its exfoliative properties;    -   extract of red vine, for its anti-blotch and decongesting        properties;    -   extract of Arnica Montana, for its anti-blotch, antiseptic and        astringent properties;    -   hyaluronic acid, for its hydrating action;    -   organic silicon;    -   green tea, for its anti-radical and astringent properties;    -   extract of carrot root, rich in vitamins B1, C and E;    -   extract of bearberry, which contains arbutin, known for being a        melanin inhibitor;    -   the HPS3® molecule, obtained from a purified extract of the alga        Padina Pavonica, and capable of stimulating synthesis of glucose        aminoglycanes, essential in skin hydration;    -   lidocaine, xylocaine.

1. A method for the treatment, in particular cosmetic, of an area of theskin of a human subject transepidermally, characterised in that itcomprises the step consisting of spraying a pressurised liquid onto thearea to be treated, by means of a spray nozzle (25).
 2. A methodaccording to claim 1, characterised by the fact that the liquidcomprises water or saline.
 3. A method according to claim 2,characterised by the fact that the liquid comprises at least oneadditive.
 4. A method according to any one of claims 1 to 3,characterised by the fact that the step consisting of spraying a liquidonto the area to be treated comprises spraying at a pressure such thatthere is no risk of breaking the skin in the, said area, whilst imposinga maximum pressure for effective penetration of the said liquid.
 5. Amethod according to claim 4, characterised by the fact that the pressureis between 5 and 70 bar, in particular between 10 and 25 bar.
 6. Amethod according to claim 1, characterised in that it comprises the stepconsisting of sucking the sprayed liquid with a view to discharging it.7. A method according to claim 6, characterised in that the auction stepis performed by means of an annular suction chamber (27).
 8. A methodaccording to claim 1, characterised in that it comprises the stepsconsisting of filtering the liquid and recycling it.
 9. A methodaccording to claim 1, characterised in that the step consisting ofspraying a pressurised liquid onto the area to be treated, by means of aspray nozzle (25), is preceded by a step of abrading the stratumcorneum.
 10. A device for treating an area of the skin of a humansubject transepidermally, comprising a hand piece (5) and a spray nozzle(25) mounted on the said piece (5), characterised by the fact that itcomprises means of pressuriaing a liquid, and at least one conduit (14)disposed by the pressurisation means and the spray nozzle (25).
 11. Adevice according to claim 10, characterised by the fact that thepressurisation means comprise a pump (6).
 12. A device according toclaim 10, characterised by the fact that the pressurisation meanscomprise a bag (4) able to receive the said liquid and a chamber (12)able to receive the said bag (4).
 13. A device according to any one ofclaims 10 to 12, characterised by the fact that it comprises an annularsuction chamber (27).
 14. A device according to claim 13, characterisedby the fact that it comprises an end piece (30) which can be unscrewedor detached, delimiting the said chamber (27) open towards the outside,and means, for producing a vacuum in the said chamber (27).
 15. A deviceaccording any one of claims 10 to 12, characterised by the fact that itcomprises filtration means (21)
 16. A hand piece for a device accordingto any one of claims 10 to 12, characterised in that it comprisescontrol means arranged so as, in the idle position of the said handpiece, to stop the pressurised liquid by contact of the end (32) of apiston (36) on a piece (33) and, in the position of use, to move awaythe said end (32) of the piece (33), so as to release the liquid inorder to supply the spray nozzle (25).